title: Diagnostic usefulness of ¹⁸F-FAMT PET and L-type amino acid transporter 1 (LAT1) expression in oral squamous cell carcinoma.
abstract: OBJECTIVE
  L-[3-(18)F]-α-Methyltyrosine ((18)F-FAMT) was developed as an amino acid tracer for PET imaging to provide better specificity than 2-[(18)F]fluoro-2-deoxy-D-glucose ((18)F-FDG) PET for cancer diagnosis. We investigated the diagnostic usefulness of (18)F-FAMT in oral squamous cell carcinoma (OSCC). The correlation between tumour uptake of (18)F-FAMT and L-type amino acid transporter 1 (LAT1) expression was determined.
  
  
  METHODS
  The study group comprised 68 OSCC patients who underwent both (18)F-FAMT and (18)F-FDG PET. Resected tumour sections were stained by immunohistochemistry for LAT1, CD98 and Ki-67, and microvessel density was determined in terms of CD34 and p53 expression.
  
  
  RESULTS
  The sensitivity of primary tumour detection by (18)F-FAMT and (18)F-FDG PET was 98 % and 100 %, respectively. The sensitivity, specificity and accuracy of (18)F-FAMT PET for detecting malignant lymph nodes were 68 %, 99 % and 97 %, respectively, and equivalent values for (18)F-FDG PET were 84 %, 94 % and 94 %, respectively. The specificity and accuracy of (18)F-FAMT were significantly higher than those of (18)F-FDG. The uptake of (18)F-FAMT was significantly correlated with LAT1 expression, cell proliferation and advanced stage. The expression of LAT1 in OSCC cells was closely correlated with CD98 levels, cell proliferation and angiogenesis.
  
  
  CONCLUSIONS
  (18)F-FAMT PET showed higher specificity for detecting malignant lesions than (18)F-FDG PET. The uptake of (18)F-FAMT by OSCC cells can be determined by the presence of LAT1 expression and tumour cell proliferation.
authors.affiliation: Department of Stomatology and Maxillofacial Surgery, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan.
authors.forename: Aiko
authors.initials: A
authors.lastname: Nobusawa
authors.forename: Mai
authors.initials: M
authors.lastname: Kim
authors.forename: Kyoichi
authors.initials: K
authors.lastname: Kaira
authors.forename: Go
authors.initials: G
authors.lastname: Miyashita
authors.forename: Akihide
authors.initials: A
authors.lastname: Negishi
authors.forename: Noboru
authors.initials: N
authors.lastname: Oriuchi
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Higuchi
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Tsushima
authors.forename: Yoshikatsu
authors.initials: Y
authors.lastname: Kanai
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yokoo
authors.forename: Tetsunari
authors.initials: T
authors.lastname: Oyama
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000378:metabolism; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D027283:Large Neutral Amino Acid-Transporter 1 / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008781:Methyltyrosines / Q000493:pharmacokinetics*; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*
chemical_list: C105991:3-fluoro-alpha-methyltyrosine; D027283:Large Neutral Amino Acid-Transporter 1; D008781:Methyltyrosines; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18